The present invention generally relates to a capsule orientation control and more particularly, to a method of controlling orientation or attitude of a plurality of capsules in a predetermined orientation and an apparatus employed therefor.
As is generally known, for example, in the gelatin hard capsules for use in the pharmaceutical industry each composed of a cylindrical open-ended body and a cap similar in shape to the body and applied onto the body with the open end of said body inserted into said cap, the cap and body are formed separately by dip molding so as to be mechanically combined thereafter into one unit for subsequent visual examination, while the peripheral surface thereof (normally, the peripheral surface of the cap) is further imprinted, if necessary, with proper indications such as article codes, names of pharmaceutical companies, etc. The capsules thus prepared are first supplied to a pharmaceutical company where a predetermined dose of an oral medicine and the like is enclosed in each of the empty capsules, and after another visual examination, are packed in a suitable package such as a blistered package or the like for delivery to general markets. In connection with the above, for filling the empty capsules as described above with contents such as the doses of the medicine, it is absolutely necessary to align in advance the capsule attitude in a predetermined direction with respect to the transporting direction, i.e. to effect the orientation control for adapting the capsules to a filling machine. Meanwhile, although not essential at all times, similar orientation control to the above is also effected prior to the visual examination, printing and packing of the capsules for facilitation of the examination, neatness of the printed indications, and further, good style of final packages, etc.
Incidentally, the orientation control of capsules is broadly divided into two practices, i.e. one in which axes of the capsules are adapted to lie along, i.e. to be directed in a direction parallel to the direction of transportation of the capsules, and the other in which the axes thereof are caused to intersect at right angles with said direction of transportation.
Conventionally, owing to reasons such as ease in--therefor the orientation control or simple construction of the apparatus required for the orientation control, etc., the former practice in which the axes of the capsules are aligned with the direction of the transportation, with the caps (or bodies) of the capsules all directed forwards or backwards, has been widely employed. While the former orientation control method as described above fully meets the purposes of visual examination, and printing and filling of the contents, it is not applicable to the so-called "spin" printing which has recently been put into practical application and in which printing is effected along the cylindrical outer peripheries of the capsules (normally of the cap sides). For effectively carrying out the "spin" printing as described above, it is required to preliminarily align the capsules with their axes intersecting at right angles with the direction of transportion of the capsules as in the latter practice. Meanwhile, the conventional capsule orientation control apparatuses employed for the former practice in which the axes of the capsules are aligned with the direction of transportation of the capsules for directing all the caps thereof forwards or backwards in the above state, still have such disadvantages in that they are complicated in construction or rather unreliable in function.
In connection with the above, there has conventionally been proposed one method in which axes of capsules are adapted to intersect at right angles with the direction of transportation thereof, for example, in Japanese Patent Publication Tokkosho No. 53-12239 (corresponding to U.S. Pat. No. 3,871,295 to Ackley entitled "Capsule orienting apparatus and method of spin printing"). Although the invention disclosed in said Japanese Patent Publication relates to a method of orientation, rotation and printing of capsules and an apparatus employed therefor, the features thereof rather reside in the capsule orientation control method and apparatus employed therefor for effecting the "spin" printing described earlier.
More specifically, the known arrangement as described above comprises in short:
(i) a rotary drum having, in its peripheral surface, a large number of capsule housing pockets each composed of three recesses or dints respectively formed in a radial direction, the circumferential direction and axial direction of said rotary drum to constitute said capsule housing pocket, and
(ii) attitude correcting means including two air jetting devices for directing air jet in a predetermined direction provided adjacent to the rotary drum, and a spacer stopper plate having a slit of a predetermined width.
The functions of the prior art apparatus as described above are as follows.
(i) The pharmaceutical capsules each composed of the cap and body combined as one unit and accommodated at random in the orientation within a hopper are first received and held in the radial directed pockets of the rotary drum so that the axes thereof are directed in the radial direction of the rotary drum, with the caps thereof radially outwardly orientated in the erect posture or radially inwardly orientated in the inverted posture.
(ii) At the time point where the capsules thus held on the rotary drum have been transported a predetermined distance in the circumferential direction by the rotary drum following rotation thereof, the air jet in the direction of transportation is directed to the upper portions of the capsules slantwise from above said capsules.
(iii) In the above case, by the selecting action of the spacer stopper plate, only the capsules held in the inverted posture in the above item (i) are caused to fall down in the direction of transportation, i.e. in the circumferential direction of the rotary drum so as to position the cap portions thereof at the upper portions of the radial direction pockets for bringing said cap portions into substantially the same position as those of the capsules in the erect posture in the above item (i).
(iv) Under the above state, a second air jet is further directed to the cap portions of the respective capsules from the axial direction of the rotary drum for rotating all the capsules in a direction in which axes of the capsules intersect at right angles with the direction of transportation so as to align the cap portions thereof in the same direction.
(v) Subsequently, the respective capsules are taken out as they are in the posture of the above item (iv).
Although the prior art capsule orientation control apparatus in Japanese Patent Publication Tokkosho No. 53-12239 having the construction and functions as described in the foregoing, is only one arrangement in which the capsules are directed to intersect at right angles with the direction of transportation for the orientation control, the known apparatus has disadvantages as described hereinbelow.
(1) Since the capsule housing pockets provided on the rotary drum each includes the recesses formed in three directions of the rotary drum as described earlier, not only the processing thereof is troublesome, but the capsule treating capacity of the apparatus is not sufficiently large, since the number of said pockets per unit area of the rotary drum is limited.
(2) The attitude correction carried out by the indirect means utilizing the air jets is rather unstable in its function, and the reliability thereof tends to be markedly reduced following high speed operation of said apparatus.
(3) Especially, since the initial attitude correction is effected through the spacer stopper plate by the jetting of air stream, the function thereof is apt to be uncertain.
(4) The air jetting devices of two systems are required for the attitude correction, while each of the air jetting devices has to be provided with jetting ports corresponding in number to the number of rows of said pockets of the rotary drum, and thus, the overall mechanism of the apparatus is undesirably complicated.
(5) By the reasons as described in the above items (1) to (4), the prior art apparatus is rather unsatisfactory both in terms of accuracy and capsule treating capacity.
Similarly, the conventional capsule orientation control apparatuses in which the axes of capsules are arranged to lie along the direction of the transportation thereof also have disadvantages in that the construction thereof is still complicated and the function thereof rather unstable.